This will become clear in rest of the Part II when the various commercial solutions
currently employed to deliver Carrier Ethernet are discussed.
NOTE The focus in this book is primarily on delivering Carrier Ethernet services;
the network and transport delivery infrastructure??”the Carrier Ethernet solutions,
provide the carrier-class attributes that enable commercial Carrier Ethernet services.
Often, the term ???Carrier Ethernet??™ is interchangeably used to refer to both the Ethernet
services and the underpinning enabling solution infrastructure.
The Carrier-class attributes are delivered differently by the various network solutions
(for example, how reliability is offered in one solution versus another). This is largely a
result of their respective geneses and subsequent evolution. It is important to also note
that some of the Carrier Ethernet attributes in a solution existed pre-Carrier Ethernet
(albeit at the transport layer and not at the service layer) and were, in fact, initial drivers
for the use of respective solution. For example, SONET offered impressive resiliency
to any failures in the fiber and/or equipment deployed in a ring topology, so it was adopted
to support mission-critical voice services that required stringent SLAs.
Pages:
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186